The problem doesn't seem to be with Calibre since the books are showing up in my sent folder in Gmail, but they aren't getting to my Kindle. I sent 2 books over an hour ago, and they still haven't arrived. I never had this problem with my K3, so I'm not sure what to try next.

Have you tried sending the books directly from your email? Or another email address? It's possible the email server is delayed.

Also, the Amazon servers might be slow today. I had a 3 hour delay on a group of documents I sent to my Kindle earlier today (which I then re-sent from another email address and they were delayed as well).

Why not just plug in the USB cable and send the books straight to the PW?

You can also use the "Send to Kindle" program http://www.amazon.com/gp/help/custom...0036987&sr=1-1 to send books from your computer to your Kindle reader. All you have to do is install the program and then register it by putting in your amazon email and password and you can send multiple books at one time to your Kindle device(s).

This is why I stop using email and use Send to Kindle instead. Gmail has been acting up bad this past week so more likely it was on their end.

Yep 'Send to Kindle' is a lot more reliable than email and quicker than either that or connecting up the USB cable(IMO). Now and then I've had trouble getting a book to go through (usually I just have to reconvert the book in Calibre) but generally it works great. My K3 and PW have different email addresses associated with them which adds potential confusion, but STK simplifies things in that you just check/uncheck with of your Kindle devices you want to send the book to.

Yep 'Send to Kindle' is a lot more reliable than email and quicker than either that or connecting up the USB cable(IMO). Now and then I've had trouble getting a book to go through (usually I just have to reconvert the book in Calibre) but generally it works great. My K3 and PW have different email addresses associated with them which adds potential confusion, but STK simplifies things in that you just check/uncheck with of your Kindle devices you want to send the book to.

I never use USB because I want all the benefits of the Personal Documents Cloud. Sync Last read, Bookmarks, Notes, Highlights and Availability from the Cloud to download on other Kindles and apps.

Every Kindle has a unique email address. The email address is the way that Amazon determines which device to send the book to.

True, but what I meant HarryT is that with the STK application I can send a book that I got from here at MR to both my Kindles (if I want) just by having both checkboxes checked. Otherwise I have to either send two separate emails or connect/disconnect both of my Kindles to the computer via USB to do it.

I never use USB because I want all the benefits of the Personal Documents Cloud. Sync Last read, Bookmarks, Notes, Highlights and Availability from the Cloud to download on other Kindles and apps.

I don't like to sideload because it's a pit of a pain. I'd rather just click a couple of buttons. Until your post, though, I didn't realize that I would be missing out on the benefits of cloud if I did it that way. Thanks!

Maybe I'm daft, but I seem to have read at some point in time that e-mailing stuff to your Kindle e-mail address actually costs money for each item you send, and it costs extra if the file needs to be converted to Mobi/AZW.

Was this ever the case, is it still the case, does it only apply if you download through 3G.... I am not completely sure. If it costs money, then mailing a load of stuff to your Kindle could walk into the papers (*).

(*) That was an intentionally written, direct 1-to-1 translation of the Dutch proverb "In de papieren lopen", which means something costs much more money than intended.